The effect of feeding with a tryptophan-free amino acid mixture on rat liver nuclerribonuclec acid nucleotidyltransferase

1969 ◽  
Vol 114 (2) ◽  
pp. 41P-42P ◽  
Author(s):  
A R Henderson
1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.


1997 ◽  
Vol 272 (3) ◽  
pp. R991-R994 ◽  
Author(s):  
R. Stancampiano ◽  
F. Melis ◽  
L. Sarais ◽  
S. Cocco ◽  
C. Cugusi ◽  
...  

The effect of oral administration of a tryptophan-free amino acid mixture or the same mixture containing tryptophan (Trp) on hippocampal serotonin (5-HT) extracellular levels was studied using in vivo brain microdialysis of freely moving rats. During chloral hydrate anesthesia rats were implanted with dialysis probes in the dorsal hippocampus, and experiments were performed 24 h later. In vehicle-treated rats, the extracellular levels of 5-hydroxyindolacetic acid (5-HIAA) and 5-HT did not change during 240 min after ingestion. Oral administration of the Trp-free amino acid mixture significantly decreased basal 5-HT and 5-HIAA output 100 min after ingestion (65 and 81% of basal value, respectively) and remained at this level for another 140 min. The amino acid mixture containing Trp failed to significantly change basal extracellular levels of 5-HT, but enhanced that of 5-HIAA by approximately 134%. Moreover, in rats receiving the Trp-free amino acid mixture, the increase of hippocampal 5-HT release induced by d-fenfluramine (206%) was smaller than that released by the same drug in rats receiving the nutritionally balanced amino acid mixture (271%). Thus these results show that removal of Trp from the balanced amino acid mixture decreases spontaneous and d-fenfluramine-induced release of 5-HT in the hippocampus. In conclusion, our study supports the hypothesis that the mood-lowering effect observed in man after ingestion of a Trp-free amino acid mixture is associated with diminished 5-HT release in the brain.


1994 ◽  
Vol 153 (7) ◽  
pp. 501-503 ◽  
Author(s):  
M. -E. Herrmann ◽  
H. G. Brösicke ◽  
M. Keller ◽  
E. Monch ◽  
H. Helge

1974 ◽  
Vol 20 (6) ◽  
pp. 431-436
Author(s):  
Hiroshi ITOH ◽  
Tetsuya KISHI ◽  
Masahiro EMA ◽  
Ichiro CHIBATA

2017 ◽  
Vol 96 ◽  
pp. 138-145 ◽  
Author(s):  
Giovanni Corsetti ◽  
Claudia Romano ◽  
Evasio Pasini ◽  
Emanuele Marzetti ◽  
Riccardo Calvani ◽  
...  

1971 ◽  
Vol 41 (1) ◽  
pp. 23-33 ◽  
Author(s):  
A. M. Asatoor ◽  
M. R. Crouchman ◽  
A. R. Harrison ◽  
F. W. Light ◽  
L. W. Loughridge ◽  
...  

1. The intestinal transport of oligopeptides containing either lysine or arginine has been compared with that of the corresponding free amino acids in six homozygous cystinuric patients and in six normal adult subjects by use of the oral tolerance test technique. 2. No difference was found in the absorption of lysine from l-lysylglycine and an equivalent mixture of free lysine and glycine. 3. In comparisons of serum increments of lysine and arginine after oral casein and an equivalent free amino acid mixture there was no difference in the case of lysine but rise of serum arginine was higher in three cystinuric patients after the whole protein than after the amino acids. 4. Studies of urinary piperidine and pyrrolidine output in a single cystinuric patient supported the results of the tolerance tests. 5. Absorption rates of the dipeptides l-lysylglycine and l-arginyl-l-aspartate from an isolated loop of rat gut are compared with those of an equivalent free amino acid mixture. No difference was found for the former peptide, but in the latter absorption rates of arginine were higher after the amino acid mixture.


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